The groom's a no-show
Wrong move: Loudly run down a list of why you never liked him in the first place and offer to set up the bride with your very available older brother.
Right move: Help usher out the guests as quickly as possible; be on standby with tissues, vodka.
No one is mentioning that the bride is eight months pregnant
Wrong move: Crack a fat joke, pat her belly, and wink at the groom before marveling at her chutzpah for donning a white wedding dress.
Right move: Thanks to Knocked Up, Juno, and those ceaselessly spawning celebs, big-bellied is the new black anyhow. Congratulate! (After you confirm with another guest that the groom is, in fact, the proud baby daddy.)
The bride's intoxicated ex attempts to make a toast
Wrong move: Start a screaming match with him in front of everyone about how he's ruining things for her. Just. Like. Always.
Right move: Loop an arm over his shoulder and join in, "Well, Joe, we all have some hi-larious stories. Remember that time . . ." while wrestling the mike from his drunken death grip.